Island



@(No ModeL)" F. SPALDING.

(JALIPERS No. 591,363. Patented Oct. 5,1897.

mama-55:5: W4.

pzrzns cu. mmo-Lrmovv WASHINGTON u c UNITED STATES ATENT FFIcE.

FRANK SPALDING, OF PROVIDENCE, RI-IODE ISLAND, ASSIGNOR TO THE BROWN &SHARPE MANUFACTURING COMPANY, OF SAME PLACE.

CALIPERS.

SPECIFICATION forming part of Letters Patent No. 591,363, dated October5, 1897.

Applioation filed May 6,1897. Serial No. 635,360. (No model.)

To all whom it may concern:

Be it known that I, FRANK SPALDING, of Providence, in the county ofProvidence and State of Rhode Island, have invented a new and usefulImprovement in Calipers; and I hereby declare that the following is afull, clear, and exact description of the same, reference being had tothe accompanying drawings, forming part of this specification.

, The invention has reference to an improvement in spring-calipers inwhich the legs are forced apart by the action of a spring and areadjusted by a thumb-nut in screw-threaded engagement with a rodpivotally secured to one of the legs.

The invention consists in the peculiar and novel construction of thethumb-n ut,whereby the adjustment of the calipers is facilitated, asWill be more fully set forth hereinafter.

Calipers have to be so often adjusted and frequently to greatly-varyingdistances that the time required to turn the thumb-nut on thescrew-threaded rod connecting the two legs of the calipers forms aconsiderable part of the employees time. To avoid this loss of time, thethumb-nut has been made in the form of a sleeve, on which jaws providedwith screwthreads were pivoted and arranged to slide on thescrew-.threaded rod from point to point. By engaging the jaws with thescrew-thread the final adjustment was then made. In these prior devicesthe adjustment was not as convenient as is desirableand the longitudinaljoints in the thumb-nut were objectionable in use.

The object of my invention is to avoid these defects and produce arapidly-adj ustable nut more convenient in use and better adapted forminute adjustment.

Figure 1 isv a side view of a spring-caliper provided with my improvedadjusting thumbnut. Fig. 2 is a sectional view showing thescrew-threaded rod and the improved thumbnut in connection with two legsof a caliper.

Fig. 3 is a side view of the internally-screwthreaded split nut,'andFig, 4 is an end view of the same. Fig. 5 is a vertical section, andFig. 6' a transverse section, of the hinged end -of the caliper-legs.

In the drawings, a, (1 indicate the two legsof the calipers; b, thehinged connection formed is conical.

by a convex projection on one leg and a concaved seat on the other. Apin extends through the convex projection, and two washers, one on eachside of the legs, are secured together by the pin. 0 indicates aring-spring seated in notches formed on the outside of the legs a aabove the hinged joint. The screwthreaded rod cl is pivotally secured atone end to one leg and extends through a hole in the other leg. Theconical cup 6, rounded at its smaller end, slides freely over thescrewthread of the rod and bears against the leg a. The split nut f isinternally screw-threaded at the end g. The other portion of this endClose to the flange h the split nut is provided with the groove 1'. Thenut f is split into four equal parts, as is shown in Fig.

4:, and is split close up to the flange h, which flange is solid. A holeslightly larger than the screw-threaded portion of the rod (1 extendsthrough the nut f from the screw-threaded end 9 through the flange h.

The flange h is firmly secured in the end of the sleeve is, so as toturn with the same and the peripherically-milled flange Z,by which thedevice is operated. The knob m is secured to the end of thescrew-threaded rod 01 and prevents the accidental Withdrawing of theadjusting device.

The operation of the adjusting device on the calipers is as follows: Thespring 0, pressing on the legs above the fulcrum, forces the lower endsof the legs apart. The conical cup 6 compresses the conical end of thesplit nut f and engages the same with the screwthread of the rod 01, andthe end of the sleeve it bears against the end of the conical cup e. Byturning the flange l the nut fturns on the screw-thread and the ends ofthe caliper-legs are brought closer together or allowed to spreadfarther apart and may be accurately adjusted. When a greater differencein adjustment is required, the legs are slightly compressed, whereby thecup 6 slides on the conical endg and allows the nut f to open and thenut with the sleeve is to slide on the screwthread. By releasing thelegs the springpressure forces the cup e again over the conical end g,and the final adjustment is made by turning the milled flange Z. Thesleeve is incloses and protects the split nut and facilitates the use ofthe device, as the exterior is smooth and round.

The split nut f is made of steel and is spring-tempered. The groove 1',by diminishing the thickness of the metal at the end of the cut,increases the flexibility of the ends 9 of the nut. The sleeve 70 limitsthe expansion of the ends g and the breaking off of parts of the splitnut f in handling.

Having thus described my invention, I claim as new and desire to secureby Letters Patent 1. In a spring-caliper, the combination with the legsa a and the screw-threaded rod (1 pivotally secured to one leg andextending through an opening in the other leg, of the conical cup 6, thesleeve 7; having the peripherically-milled flange Z, the split nut fhaving the conical end 9, the groove 2' and flange 7L, the flange h andthe sleeve 7; being secured together, as described.

2. In a caliper, the combination with the legs a a, the fulcrum l), thespring 0 acting on the legs above the fulcrum, and the screwthreaded rod(Z pivotally secured to one leg and extending through an opening in theother, of the conical cup e, the sleeve 70, the peripherically-milledflangel on the sleeve, the longitudinally-split nut f, the conical endg, the groove and flange h integral with the split nut f, said flange hsecured to and rotating with the sleeve 7c and the knob m on the end ofthe rod; whereby the adjustingnut may be rapidly moved longitudinally onthe screw-threaded rod d, as described.

In witness whereof I have hereunto set my hand.

FRANK SPALDING.

\Vitn esses:

JosEPH A. l\.[ILLER, Jr., M. F. BLIGH.

